SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12f3993fdf483d5853f274a861f3c33c9999a06ae4eca272a06aa1bd51ed204a' 
  AND token = 'gvk89CrvtLOavBNfpUssf/7SSrI0A/05HqnTeX9mgxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}